115 research outputs found
Confirmation Of Fatal Mycoplasma Pneumoniae Infection By Polymerase Chain Reaction Detection Of The Adhesin Gene In Fixed Lung Tissue
No full textCorrespondenceJ. Williamson, B. P. Marmion, T. Kok, R. Antic, and R. J. Harri
Positive feedback regulation of wishful thinking shapes bone morphogenetic protein signaling in the follicular epithelium
No full textMorphogenesis is preceded by an extensive gene patterning that is regulated by a small number of signaling pathways. One such pathway, the Bone Morphogenetic Protein (BMP) pathway, is an essential developmental regulator in many organisms throughout Eukarya, including Drosophila melanogaster. An established system to study patterning that is regulated by cell-to-cell signaling is D. melanogaster oogenesis. A two-dimensional monolayer of follicle cells (FCs) surrounds the developing oocyte, becomes patterned and later folds into eggshell structures; this process is regulated, in part, by BMP signaling. While BMP signaling in the FCs is associated with the patterning of the type I receptor, thickveins (tkv), the cooperating type II receptor remains unknown. Here, I aimed to establish its identity. Though previously only reported during embryonic neurogenesis, I found that the type II receptor, wishful thinking (wit), is expressed in an evolutionary conserved pattern in the FCs of species that diverged over 45 million years. Also, WIT is self-regulated by a positive feedback loop, which I demonstrate works to sharpen the BMP signaling gradient. Of importance, null clones of WIT coincide with a cell autonomous loss of BMP signaling, monitored by the phosphorylated form of the intercellular signaling molecule MAD (P-MAD). Loss of WIT has changes the patterning of Broad, a marker for dorsal appendages, affecting eggshell morphology. These results demonstrate an active role for WIT in non-neuronal tissue, and establish WIT as the type II receptor working in concert with TKV during FC patterning.M.S.Includes bibliographical references (p. 16-20)by Robert MarmionIncludes abstrac
A cohort study of duplex Doppler examinations of the carotid artery in primary open angle glaucoma
No full textObjectives To explore the possibility of pathological change in the common carotid artery at the bifurcation and in the internal carotid artery beyond the bifurcation which could contribute to a reduced diastolic pressure as observed in primary open angle glaucoma.
Design Duplex ultrasonic examinations of carotid bifurcations were conducted on 80 patients. Carotid artery defects were allocated into three types: no demonstrable flow defects, internal carotid artery abnormalities and disease in the carotid bulb.
Setting Bristol Royal Infirmary Vascular Laboratory.
Participants Eighty patients (mean age 69.6 years) providing a total of 160 sides to the analysis.
Main outcome measures An estimated central retinal artery pressure, intraocular pressure and field loss were recorded for each side measured.
Results Doppler investigations revealed significant levels of pathological change in the internal carotid distinct from changes at the carotid bulb. The disease revealed in the internal carotid artery was significantly associated with intraocular pressure (p = 0.032), with an effect small to medium in magnitude. The Q2 measure, derived from mean arterial pressure and intraocular pressure, was also substantively associated with disease in the internal carotid artery. Both intraocular pressure and the Q2 measure effectively discriminated between groups, with field loss providing rather less discriminating capability. There was a strong trend towards a higher intraocular pressures and a greater visual field loss with internal carotid artery disease.
Conclusions Pathological changes in the extra cranial carotid artery in primary open angle glaucoma exceed those in the arteries classified as normal. The presence of disease specifically in the internal carotid artery emphasised the need for a mechanism for the evaluation of the internal carotid apart from the carotid bulb. A basis for clarifying the presence of an ischaemic zone is proposed
Understanding heritage: multiple meanings and values.
No full textThis research aims to explore the ways in which people understand and value heritage through a focus on the lay rather than the expert view. This focus was considered important in order to move beyond the emphasis on expert knowledge within heritage discourses and in turn, privilege lay understandings of heritage. This study adds to current knowledge by offering an in-depth understanding of the non-expert view of heritage and the multiple meanings and values that heritage represents within this context. The rationale for this research is based on the increasingly important role heritage plays within the wider visitor economy and the recognised interrelationships between heritage and tourism. In order to develop long-term, meaningful relationships with current and potential heritage audiences, there is a need to appreciate the ways in which people engage with heritage in a much broader sense and to understand the meanings and relevance that heritage may represent within this context. In order to meet the aim of this research, an inductive qualitative methodology was designed which prioritises the emic or insider perspective of heritage. To further enhance the inductive nature of this study, the primary research took place away from a pre-defined „heritage’ context in order to allow the participants themselves to define and shape heritage as they understand and value it. Eight focus groups were carried out with forty-seven members of the public and the data was analysed through a thematic framework. Nine themes and related sub-themes were constructed to represent the lay understandings, meanings and values of heritage. The social nature of the focus group method, along with the interaction it fosters between participants, led to a range of insights about the relevance of heritage. The majority of heritage research to date has taken place within a pre-defined heritage context, which inevitably limits the scope for accessing and understanding the views of those who do not typically engage with heritage in this way. Therefore, this study further contributes by incorporating the views of those who do not typically fall within heritage user or visitor categories. By exploring the views of the so called non-user or non-visitor of heritage the barriers that prevent engagement with „heritage‟ and „heritage tourism‟ as it is defined and presented by the industry are identified. The implications of this study relate to the need for more engaging and personally relevant heritage narratives that build from an understanding of the meanings and values that shape engagement with heritage beyond a personal level. Heritage practitioners and academics need to embrace lay understandings of heritage within their activities and seek to empower current and potential audiences to critically engage with and actively interpret meanings from the heritage they present
Carbohydrates in hepatitis B antigen
No full textLetter to the EditorAbstract not availableC. J. Burrell, Elaine Proudfoot, G. A. Keen & B. P. Marmio
Mycoplasma pneumoniae: acute illness, antibiotics, and subsequent pulmonary function
No full textOne hundred and eight children presenting with Mycoplasma pneumoniae infection were assessed during the acute illness and followed for three years. The incidence of wheezing with the acute infection (40%) was greater than expected in a normal childhood population. The initial illness precipitated wheezing for the first time in some subjects but others wheezed only with the acute illness. In non-asthmatic subjects significant bronchodilator responsiveness was present one month after infection. Children given erythromycin during the first seven days of their illness had a significantly shorter fever duration compared with those treated inappropriately. No significant effects of treatment were noted on pulmonary function three years later but non-asthmatic children had abnormal mean forced expiratory volume in one second and forced expiratory flow after 50% of the expired vital capacity compared with 64 healthy controls. These findings indicate impaired function three years after initial infection.A R Sabato, A J Martin, B P Marmion, T W Kok, and D M Coope
Laboratory diagnosis of Mycoplasma pneumoniae infection: 3. Detection of IgM antibodies to M. pneumoniae by a modified indirect haemagglutination test
No full textThe indirect haemagglutination (IHA) test was compared with the complement-fixation (CF) test for the measurement of antibodies to Mycoplasma pneumoniae. A modification of the IHA was used to measure M. pneumoniae IgM antibodies. Sera were obtained from various groups of patients who were either culture or antigen positive for M. pneumoniae in nasopharyngeal aspirates or who had fourfold or greater increase in CF antibody or a titre greater than or equal to 320. The results of these comparisons showed that the modified IHA test was specific and more sensitive (89% as opposed to 64%) than the CF test. The modified IHA test for the detection of IgM antibody was highly effective in the recognition of recent or current infection with the mycoplasma. It was also of equal sensitivity to an indirect enzyme immunoassay for the detection of IgM antibodies to M. pneumoniae.T.-W. Kok, B. P. Marmion, G. Varkanis, D. A. Worswick and J. Marti
Laboratory diagnosis of Mycoplasma pneumoniae infection: 2. Comparison of methods for the direct detection of specific antigen or nucleic acid sequences in respiratory exudates
No full textThe efficiency of the direct detection of Mycoplasma pneumoniae in respiratory exudates by an antigen capture, indirect enzyme immunoassay (Ag-EIA), has been compared with its detection with a cDNA probe ('Gen-Probe assay') directed against the specific ribosomal RNA sequences of the organism ('Mycoplasma pneumoniae Rapid Diagnostic System', Gen-Probe, San Diego, California). Both assays showed excellent specificity against a range of mycoplasma species suspended in negative nasopharyngeal aspirates; only M. pneumoniae and M. genitalium reacted. In experiments with graded doses of viable M. pneumoniae cells suspended in negative nasopharyngeal aspirate, the Gen-Probe assay was more sensitive than Ag-EIA; detection limits were respectively 2 X 10(3) c.f.u./ml (3.2 X 10(5) genomes) and 2.5 X 10(4) c.f.u./ml (4 X 10(6) genomes); detection levels 10-100 times less sensitive than culture. The two assays were also tested on nasopharyngeal aspirates or sputum specimens from 90 patients with respiratory infection; 67 of these were culture- or seronegative for M. pneumoniae and 23 were culture- or seropositive. Ag-EIA detected 21 (91%) of the latter but the Gen-Probe assay detected only 5 (22%). Both assays were negative with the 67 culture-/sero-negatives; there were no Gen-Probe assay positive/Ag-EIA negatives. Overall, it is concluded that although Ag-EIA and the Gen-Probe assay are effective substitutes for culture as a diagnostic procedure, there is a significant problem with samples which are culture-negative and from patients who have good serological evidence of current infection. Possible reasons for the disparity between the two assays are advanced.R. Harris, B. P. Marmion, G. Varkanis, T. Kok, B. Lunn, and J. Marti
Laboratory diagnosis of Mycoplasma pneumoniae infection: 1. Direct detection of antigen in respiratory exudates by enzyme immunoassay
No full textDirect and indirect antigen capture enzyme immunoassays (Ag-EIA) have been developed for the detection of Mycoplasma pneumoniae in nasopharyngeal aspirates or sputum from respiratory infection. The sensitivity of the two Ag-EIA were similar, but the indirect method using polyclonal rabbit and guinea-pig antisera was more convenient. The Ag-EIA had a detection limit of 10(4-4.5) colony-forming units/ml of sample. It was specific for M. pneumoniae and gave a low level response with M. genitalium. There were no cross-reactions with 10 other species of mycoplasmas. Tests with a wide range of bacteria and chlamydia group antigen, representing agents sometimes found in the respiratory tract, were also negative. At the current level of development, the Ag-EIA detected about 90% of specimens that were also positive for culture; 43% of specimens from culture-negative--seropositive patients gave a positive result. The overall pattern of results indicated that while antigen detection is a quick and effective substitute for the slow culture method, serological examination for specific IgM antibody is also necessary to give a complete diagnostic coverage.T.-W. Kok, G. Varkanis, B. P. Marmion, J. Martin and A. Esterma
Experience with Newer Techniques for the Laboratory Detection of Mycoplasma pneumoniae Infection: Adelaide, 1978–1992
No full textEfforts to improve laboratory diagnostic methods for infection due to Mycoplasma pneumoniae have involved the use of a cell-sheet culture method and a modified indirect hemagglutination method for IgM antibody, while direct detection of mycoplasma has employed antigen capture-enzyme immunoassay (Ag-EIA) and polymerase chain reaction (PCR) amplification of sequences within the P1 and 16S ribosomal RNA genes and quantification of the amplified DNA by dot blot hybridization (DBH). Cell-sheet culture was slightly more sensitive and more rapid than culture with cell-free diphasic medium. Indirect hemagglutination detection of IgM antibody to M. pneumoniae was more sensitive than CF and EIA for detection of IgM antibody to mycoplasma. Ag-EIA gave a rapid and reasonably sensitive indication of infection and correlated well with a serological response of patients indicating a current infection. PCR-DBH was a highly sensitive substitute for culture of mycoplasma. Both Ag-EIA and PCR-DBH require confirmation by assessment of serological response to verify that the infection is current and that positive results of PCR-DBH, in particular, are not the result of continuing carriage of the organism from a previous infection, unrelated to the current episode under investigation.B. P. Marmion, J. Williamson, D. A. Worswick, T.-W. Kok, and R. J. Harri
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